直流电沉积Ni-W-P镀层研究

Study on Direct-Current Electroplated Ni-W-P Layer

摘要:

采用直流电沉积法，在低碳钢表面成功沉积Ni-W-P镀层。应用X射线荧光（XRF）、扫描电子显微镜（SEM）、俄歇电子能谱（AES）、X射线衍射（XRD）仪等方法，研究电流密度、镀液pH值和镀液温度对Ni-W-P镀层成分、表面形貌和结构的影响。结果表明，电流密度和镀液pH值的变化对Ni-W-P镀层成分的影响很大，而电流密度、镀液pH值和温度对镀层厚度的影响较小。电流效率随着电流密度和镀液温度的增大分别降低和升高，而随着镀液pH值的变化，在pH=7.0时有极大值。镀液pH值对Ni-W-P镀层结构有较大影响，在pH=8.0时，镀层呈现明显的Ni（111）峰，此时镀层硬度达到极大值7130 MPa。在此基础上，对Ni-W-P镀层的电沉积机制做了进一步探讨。

Abstract:

Ni-W-P layers were formed on a low-carbon steel substrate by direct-current electroplating method. The effects of current density, pH value and bath temperature on the composition, surface morphology, and microstructure of Ni-W-P layers were studied by X-ray fluorescence (XRF), scanning electron microscope (SEM), auger electron spectroscopy (AES) and X-ray diffraction (XRD). The results indicate that the change of current density and pH value influenced the composition of Ni-W-P layer greatly, but the change of current density, pH value and bath temperature hardly influenced the thickness of Ni-W-P layer. As current density and bath temperature increased, current efficiency decreased and increased, respectively, and current efficiency reached the maximum value when pH value is 7.0. The structure of Ni-W-P layer was greatly influenced by pH value, and a well-preferred orientation along Ni (111) direction was shown when pH value was 8.0. Synchronously, the microhardness of Ni-W-P layer reached the maximum value of 7130 MPa. At last, electroplating mechanism of Ni-W-P layer was discussed further.